Successful implantation and pregnancy appear to be highly dependent on appropriate adaptations in maternal hemodynamics. The protocol examined the changes through the menstrual cycle for two hemodynamic parameters. The first was uterine artery blood flow as measured by Doppler sonography, the second was the change in plasma volume, measured by the Evans Blue technique. We examined 20 women at 3 time points through each of 2 menstrual cycles. Ten women subsequently conceived and these women were examined at 4, 6 and 12 weeks of pregnancy for both uterine hemodynamics and blood volume. The project has been completed as of June 1998. The uterine hemodynamic observations has served as preliminary data for one project of a program project application titled "Steroidal Modulation of Uterine Artery Function." The plasma volume findings have resulted in a new research project titled "Measurement and Evaluation of the Relationship between Pasma Volume, Basal Autonomic Nervous Activity and the Angiotensinogen Genotype in Nulligravid Women."